If you look on YouTube you will find an addon prototype developed by campell called face map (can’t find it myself but i saw it back whe he released it) . Its basically the same functionality as presto where you can animate by selecting faces on the mesh rather than selecting bones. The face maps are used by rigers instead of helpers bones. There is also a task about it link

Custom gizmos are already in 2.8. That’s why we have gizmos for the Spin tool and others, for example. Most of the work to support Face Maps in the way described in the task is already done - it’s just the last bits that are needed to make it easy to set up and use for bone selection.